Control device



April 27, 1965 Filed 001:. 8, 1962 J. L. HARRIS CONTROL DEVICE 2 Sheets-Sheet 1 amok/14km).

A ril 27, 1965 Filed Oct. 8, 1962 J. L. HARRIS CONTROL DEVICE 2 Sheets-Sheet 2 JMAMMkQH.

United States Patent 3,180,168 CONTRGL DEVICE John L. Harris, Whitefish Bay, Wis. (4753 N. Newhail St, Milwaukee, Wis.) Filed Get. 8, 1962, Ser. No. 229,111 4 Claims. (Cl. 74-465) This invention relates to timing mechanisms of the type in which a main timing shaft is driven by an electric motor and is also operated independently of such motor by a knob or other device. In such timers, it is necessary to provide some sort of clutch between the motor and main shaft to permit movement of the shaft without damaging the motor or gearing.

One object of this invention is to provide a simple, low cost and positive drive mechanism which readily permits movement of the shaft independently of the motor.

This object is achieved by providing a slotted bearing plate for the pinion which drives the main shaft. This slot is arranged at an angle approximately 45 to the center line between the pinion and main shaft. This slot extends outwardly from the main shaft in the direction that the gear on" the main shaft is driven and the pinion is pressed toward the main shaft by means of a spring. When the shaft is turned manually, the gear moves the pinion with it and the slot serves as a camming surface for separating the pinion from the gear, thus permitting movement of the main shaft.

Another object of the invention is to provide the double acting camming arrangement so that the shaft may be turned in either direction indepedently of the timing motor.

Other objects of the invention will appear from the following description and appended claims.

A full disclosure of the invention is made in the following specification and the accompanying drawings in which:

FIG. 1 is a front view of a timer mechanism embodying the invention, parts being broken away to show the internal construction thereof;

FIG. 2 is a side sectional View of the embodiment shown in FIG. 1;

FIG. 3 is a view similar to FIG. 1 of a modified form of the invention;

FIG. 4 is a side sectional view of the embodiment of the invention shown in FIG. 3

FIG. 5 is an opened front view of the invention applied to a double acting clutch mechanism;

FIG. 6 is a side sectional view of FIG. 5.

Referring to FIGS. 1 and 2, the timer includes front and back plates 1 and 2 respectively which support a switch panel 3 which carries a switch of any suitable construction. For illustrative purposes, the switch is shown as' including switchblade brackets 4 and 5 which carry switch blades 6 and 7, both of which are biased downwardly. The switch also includes a contact bracket 8. A set of contacts 9 are carried by the blade 7 and contact bracket 8. A second set of contacts 18 are carried by switch blades 6 and 7. The lower blade 6 is operated by a cam follower 12 which is carried by a shaft 13 which extends between plates 1 and 2. A biasing spring 14 serves to bias the cam follower downwardly and supplements the biasing action of the switch blade 6.

The cam follower 12 is operated by a cam 15 on main shaft 16 which is carried by the front and back plates 1 and 2. This shaft is driven by means of a gear 18. Preferably the shaft 16 is provided with a straight knurl 19 over which the cam 15 and gear 18 fit so that the cam and gear are rigidly attached to the shaft. The main shaft 16 also extends through the front plate 1 and is 'ice provided with a knob 20 so that the shaft may be rotated manually for test purposes or setting the timer.

The gear 18 is located adjacent the front plate 1 and is driven by a pinion 21 which carries a gear 22. This gear 22 in turn is driven by a pinion 23 carried by a gear 24 which is driven by the pinion 25 of a timer motor 26.

In this embodiment of the invention, the pinion 21 is elongated and is provided with a bearing portion 28 riding a slot 29 pierced in the front plate 1.

A torsion spring 30 is carried by a pin 31 attached to the front plate 1. One leg of this spring bears against the side 32 of the timer housing. The other leg of this torsion spring bears against a turned down portion 33 of the pinion 21. This turned down portion 33 of the pinion is larger than the bearing section 23 of the pinion so as to provide a shoulder for maintaining the pinion in place between the front and back plates 1 and 2.

In this embodiment of the invention, the main shaft 16 is driven in a clockwise direction as seen in FIG. 1 by the timer motor through the gears described above. The cam 15 raises the cam follower one revolution each cycle and thus operates the switch contacts once for each revolution of the timer shaft.

It will be noted that the slot 29 in the front plate 1 extends at an angle of approximately 45 to the center line between the pinion 21 and the main shaft 16. This slot extends downwardly away from the final shaft and also extends in the same general direction as the motion of the adjacent teeth on gear 18. The pinion 21 rotates counterclockwise and thus its reaction on the teeth of gear 18 is such as to pull it to the end of slot 29 closest to the gear. Thus, the pinion 21 in driving the gear 18 tends to pull itself into engagement with the gear 18 which provides a positive drive between the pinion and gear.

When the shaft is turned manually in a clockwise direction, the teeth on gear 18 move the pinion to the left. Due to the angle of the slot 29, this movement of the pinion 21 also causes a downward movement of the pinion away from gear 18. The slot 29 thus provides a camming action by which clockwise motion of the gear causes the pinion to separate from the gear and thus permits free clockwise motion of the main shaft 16 by the knob 20. The spring 30 normally maintains the pinion in engagement with the gear and yields during the camming action. As the gear 18 is manually rotated, the pinion 21 is first cammed outwardly and then drops back as each tooth passes. This gives a rachetting type action.

From the foregoing, it will be seen that the arrangement described above providesa positive one-way drive for the shaft 16 and also provides rachetting type action for permitting the shaft to-be rotated by the knob 20. In this embodiment of the invention, the rachetting type action occurs between the final gear 18 and itsdriving pinion 21.

Where a finer rachetting action is desired, the gear train may be modified so that the separation of the gears takes place at intermediate gears in the train instead of the final gears. This arrangement is shown in FIGS. 3 and 4. In this embodiment of the invention, the main shaft assembly is identical with that of FIG. 1 and includes a main shaft 16:: having a cam 15a and a gear 18a. In this case, however, the motor pinion 25a drives a gear 35 which is carried by an elongated pinion 36 which is supported between the plate 1a and 2a. This pinion 36 drives a gear 37 which is attached to a pinion 38 which drives the gear 18a. The gear 37 and pinion 33 are carried by a shaft 39 which is supported between plates 1a and 2a. The plate 1:: is provided with a slot 29a which serves as a bearing for the shaft 39 and a spring 30a serves to bias the shaft 39 to the upper end of slot 2%.

As in FIG. 1, the slot 29a is arranged at an angle of approximately 45 with the center line between the pinion 38 and the main shaft 16a. This slot 29a also extends generally in the same direction as the movement of the gear teeth adjacent pinion 38. Thus, when the shaft 16a is rotated manually in a clockwise direction, the pinion 38 is cammed away from the gear 18a just as in FIG. 1. However, this same movement also cams the gear 37 away from the pinion 36. In this embodiment of the invention, it will be noted that the gear 37 is closely adjacent the gear 18a and the camming action of gear 18a on pinion 38 has a pronounced effect in moving the gear 37. Also, the pinion 36 which drives the gear 37 is located so that the downward movement of gear 37 separates it from the pinion 36. The parts here are proportioned so that the gear 37 separates from pinion 36 before the pinion 38 is separated from gear 13a. As a result the manual rotation of the mainshaft 16a and gear 13a causes a rachetting action between gear 37 and pinion 36. Inasmuch as gear 37 rotates faster than the gear 18, the rachetting action is finer than provided by the arrangement shown in FIG. 1. This is desirable in some cases as it permits closer setting of the timer.

FIGS. and 6 show the invention applied to a timer in which it is desirable to rotate the cam shaft manually in either direction. In this embodiment of the invention, the cam shaft 40 carries a cam 41 and a gear 42. The cam 41 operates a cam follower 43 carried by a shaft 44 extending between the front and back plates 45 and 46.-

This cam follower operates a switch 47 which is carried by a switch panel 48.

A timer motor 49 is providedwith a pinion 59 which drives a gear 51 carried by a pinion 52 which is rotatably mounted between the plates 45' and 46. The bearing portion 53 of the pinion 52 extends into a rectangular hole 54 in the front plate 45. A biasing spring 55 is carried on the front plate 45 and serves to bias the front end of the pinion 52 toward the gear 42. The surface 56 of the opening 54 extends at an angle of approximately 45 with the center line between pinion 52 and gear 42. This is indicated as angle A. The surface 56 serves as a camming surface for causing the pinion 52 to release from gear 42 when the gear 42 is turned in a clockwise direction. The opening 54 is also provided with a surface 57 which extends at 45 with the center line between the gear and the pinion. This angle is indicated as B. The surface 57 serves as a camming surface for camming the pinion 52.

away from gear 42 when the gear is rotated in a counterclockwise direction.

In this embodiment of the invention, the drive between the pinion and gearing is not a one-way drive inasmuch as the shaft 40 may be turned manually in either direction. Here the tension of the spring 55 determines the driving torque between the pinion and gear.

In this embodiment of the invention, the gear 42 is shown as of the mutilated type, having a portion 69 in which the teeth are omitted. This portion 6110f the gear is arranged relatively to the notch 61 in the. cam 41 so as to disengage from'pinion 52 when the timer reaches the OFF position in which the cam follower 42 drops in thecam notch. This permits the timer motor to continue running without further rotation of the cam shaft.

In this embodiment of the invention, the releasing pinion serves as a means for permitting the timer to be manually set in either direction. It further serves as a means for insuring ready engagement of the gear and pinion when the timer is turned from the OFF position to the timing range.

If desired, a friction clutch 62 may be interposed between the gear 51 and pinion 52. If this is done, the spring 55 is made strong enough to maintain the pinion 52 in engageemnt with gear 42 when the timer is manually set. The pinion 52 now will turn relatively with the gear 51 due to the friction clutch 62. When the friction clutch 62 is used, the rectangular slot and spring 55 serve only as a means for permitting the engagement of the gear with the pinion when the timer is set.

From the foregoing, it will be seen that this invention provides a simple, positive and extremely inexpensive arrangement for securing a positive one-way rachetting drive action or even a two-way clutch action.

It is obvious that many variations may be made Without departing from the spirit and scope of the invention. It is therefore desired to be limited only by the scope of the appended claims. a

I claim:

1. In a timer mechanism, a main shaft, a pair of spaced plates, a timing motor, a gear rigidly connected to said main shaft, a pinion for driving said gear, mounting means for said pinion extending between said plates, said mounting means including a bearing in one of said plates and a slot in the other of said plates arranged to serve as a guide for guiding said pinion away from said gear when the main shaft is turned in one direction by means other than said gear, a spring arranged to press said pinion toward said gear, and means driven by said timing motor for driving said pinion.

2. A construction as set forth in claim 1 in which the last mentioned means includes a second gear attached to said pinion and driven by a second pinion, said second gear and pinion remaining in mesh when the first pinion is guided away from the first gear.

3. A construction as set forth in claim 1 in which the last mentioned means includes a second gear attached to said pinion and driven by a second pinion, said second gear and pinion being arranged to be disengaged by the movement of said first pinion.

' '4. In a timer mechanism a main shaft, a pair of spaced plates, a timing motor, a gear rigidly connected to said main shaft, a pinion for driving said gear, mounting means References (Iited by the Examiner UNITED STATES PATENTS 10/58 Dudley 74-405 4/61 Polevoy 74352 X DON A. WAITE, Primary Examiner. 

1. IN A TIMER MECHANISM, A MAIN SHAFT, A PAIR OF SPACED PLATES, A TIMING MOTOR, A GEAR RIGIDLY CONNECTEC TO SAID MAIN SHAFT, A PINION FOR DRIVING SAID GEAR, MOUNTING MEANS FOR SAID PINION EXTENDING BETWEEN SAID PLATES, SAID MOUNTING MEANS INCLUDING A BEARING IN ONE OF SAID PLATED AND A SLOT IN THE OTHER OF SAID PLATES ARRANGED TO SERVE AS A GUIDE FOR GUIDING SAID PINION AWAY FROM SAID GEAR WHEN THE MAIN SHAFT IS TURNED IN ONE DIRECTION BY MEANS OTHER THAN SAID GEAR, A SPRING ARRANGED TO PRESS SAID PINION TOWARD SAID GEAR, AND MEANS DRIVEN BY SAID TIMING MOTOR FOR DRIVING SAID PINION. 